It is well known that plants need air, water, and light for growth. It is also known that plants purify air. The purification of air through plant leaves are well known. However, the role of complex biological and bacterial process of plant's root system in breaking down air polluting chemicals and suppress the growth of microbes was only became understood in recent years.
Since the energy crisis in the 70's, new homes are being built with energy efficiency in mind. To achieve this, buildings are tend to have less air circulation with the outside air and better seal around doors and windows. The result of these changes in addition to the wide spread use of plastics, paints and other synthetic materials and chemicals, the indoor air pollution have become a serious health problem. Which resulted in the so called sick air syndrome. Several air purification planters and apparatus were proposed by U.S. patents such as U.S. Pat. Nos. 5,217,696; 5,269,094; 5,351,438; and 5,433,923. These patents suggest means to improve the interaction of air with the root system of the plants. Major deficit of these designs include 1) lack of sufficient water reservoir in the planter which increases the work of maintaining the plants, 2) relatively large variation of water level within the planter which is, in many respect, an undesirable consequence of being unable to control a constant water level in the planter.
On the market everywhere, there are many kinds of the so called "self watering" planters available to the public. There are very little difference among these planters. The basic feature of these "self watering" planters is that a small water reservoir at the bottom of the planter with a water filling opening near the bottom of the planter side wall. Perforated divider separates soil with water reservoir except that there are few studs or channels in the divider which extend down into the water reservoir and all the way to the bottom of the planter so that soil in these studs or channels were able to be submerged in the water at any given water level in the water reservoir. Capillary action of the soil were able to lift water to the root system and support plant growth. The disadvantages of these "self watering" planters include 1) the size of the water reservoir is usually small and the uncontrollable water level also change with time, 2) the bottom exposed portion of the soil and the water reservoir are directly open to the ambient air through the water refill opening and thus mildew or microbes growth is a common problem.
This invention relates to a planter insert with separate water reservoir to be placed inside a planter. It is capable of maintaining a constant water level in the planter insert. Because the water reservoir is separate to the planter insert, the size of the water reservoir may be made as big as one wishes. For planter insert with very large water reservoir, it is not practical to remove the water reservoir for refill, a special design feature is provided to enable the refill in place without spilling water.
With different features in the planter inserts, the interface areas of ambient air with the potting medium and the root system is maximized, thus enhances the effectiveness of air purification process by the root system. Optional lamp and circulation fan are also provided. The location of the fan is imbedded within the potting medium underneath the planter insert thus greatly reduced the vibration and noise level of the fan.